John thinks it won’t be long __________ he is ready for his new job.
| A．when | B．after | C．before | D．since |
. Little Jim should love _______ to the theatre this evening.
| A．to be taken | B．to take | C．being taken | D．Taking |
. They would not allow him _______ across the enemy line.
| A．to risk going | B．risking to going | C．for risk to go | D．risk going |
. There are so many kinds of tape-recorders on sale that I can’t make up my mind ____to buy.
| A．what | B．which | C．how | D．Where |
. Charles Babbage is generally considered _______ the first computer.
| A．to invent | B．inventing | C．to have invented | D．having invented |
. The missing boys were last seen _______ near the river.
| A．playing | B．to be playing | C．play | D．to play |